A small drainage on the east slopes of Mercer Island that passes through wooded and heavily altered residential landscapes. The stream is fed from springs and stormwater runoff, leading to strong seasonality in stream flow.

a 220-foot long stream reach and associated riparian corridor that was overgrown by non-native groundcovers (English ivy) and shrubs (Himalayan blackberry). The stream passed through a number of residential properties that included landscaping dominated by open lawns.

Restoration challenge

Clients wished to create a diverse native plant assemblage in the stream corridor to promote habitat and streambank protection. This project would serve as a demonstration within the community as to what individual property owners could do with their own section of the ravine.

Restoration approach

UW-REN students, working with community members, removed non-native species from the stream zone. Bioengineering with native plants was used to stabilize the streambank and woody debris was used to create instream habitat features. Native trees, shrubs, grasses, and herbs were added along with mulch for weed control with a focus on species to (1) rapidly establish a shade canopy to control reinvasion by non-native species, (2) promote succession to a mature evergreen forested wetland, and (3) create structural diversity in the vegetation for habitat. Communities were installed to fit the varying hydrology across the stream corridor.